高氨氮废水短程硝化过程中污泥膨胀的研究.pdf

高氨氮废水短程硝化过程中污泥膨胀的研究 侯巧玲 1,2 文一波 2 李林宝 1 于 蓉 1 1.兰州交通大学环境与市政工程学院, 甘肃 兰州 730070;2.北京桑德环保集团, 北京 101102 摘要 采用 A O 工艺处理模拟高氨氮废水, 在一定条件下实现了稳定的短程硝化 积累率≥80 , 污泥沉降性能良 好, 短程硝化后期污泥沉降性能逐渐恶化。 实验结果表明 , 通过补充废水的N P 虽然能够略微降低SVI, 但是仍然不能 有效的缓解污泥膨胀。 当 COD 负荷0. 27 kg kgd 时发生污泥膨胀。 将 DO 控制在 1. 5～ 2. 0 mg L, 沉淀池的固液分 离效果良好, 并且氨氮去除率、COD 去除率和亚硝氮积累率均90, 污泥膨胀现象得到有效控制。 关键词 短程硝化 污泥膨胀 A O 工艺 0 引言 短程硝化反硝化生物脱氮是一条新型生物脱氮 途径 [ 1] ,然而低溶解氧条件下的污泥膨胀是制约短程 硝化在实际工程中应用的因素之一。本实验着重研 究了低溶解氧条件下实现短程硝化时出现的污泥膨 胀问题及相应的解决办法 。 1 实验部分 1. 1 实验水质和污泥状况 本实验所用高氨氮废水为模拟废水 ,即在自来水 中加入一定量的 NH4Cl 、NaH2PO4、CH3OH 、以及少量 微量元素, 废水的 C N 约为 3∶ 1, 用 NaOH 和 NaHCO3 调节好氧池的 pH 值 。污泥取自北京某污水处理厂。 培养驯化初期污泥呈黄褐色, 沉降性能良好, SV 40,SVI 98. 9 mL g ,镜检时发现长颈虫、轮虫以及 钟虫等原生和后生动物, 污泥处于成熟期,活性较好。 1. 2 实验装置 实验采用一体式 A O 装置,流程见图 1。 1进水箱; 2缺氧池; 3好氧池; 4沉淀池; 5pH 调节仪; 6碱液池; 7进水泵; 8硝化液回流泵; 9污泥回流泵; 10鼓风机; 11搅拌机; 12曝气装置。 图 1 实验装置流程 反应器由不锈钢制成,缺氧池、 好氧池有效容积分 别为 20、 48 L 。污泥回流比为 100,硝化液回流比为 200。好氧池内置悬浮填料,填料投配率为 20。 2 实验结果及讨论 2. 1 短程硝化初期的污泥性状 系统从氨氮浓度为 48. 83 mg L 开始启动, 约1 周 后氨氮去除率达 89. 5。系统运行稳定后开始逐步 提高氨氮浓度至 800 mg L 。在全程硝化的基础上控 制温度为 27～ 30℃, pH 值 7. 5～ 8. 6,溶解氧 0. 5～ 1. 0 mg L 的条件下约 1 周后逐渐形成了亚硝氮的积累 积累率 52. 4 , 在此期间氨氮去除率降低到 50 以下 。随着菌种对环境的逐步适应 ,稳定后的短程硝 化氨氮、 COD 平均去除率分别为 96. 8、 93. 2, 亚硝 氮平均积累率为 90. 5。污泥容积指数 SVI 随时间 变化的曲线如图 2 所示 。 图 2 SVI 随时间变化 在短程硝化初期 SVI 值均 0. 27 kg kgd 时发 生了明显的污泥膨胀 ,因此在实际运行过程中应适当 控制 COD 负荷 。导致污泥膨胀的 DO 与活性污泥的 图 4 COD 负荷与SVI 的关系 有机负荷关系, 如表 1 所示 [ 7] 。 表 1 有机负荷率与“ 安全”DO 浓度的关系 有机负荷率 kgkg - 1d- 1 “安全”DO 浓度 mgL- 1 0 . 301. 0 0 . 502. 0 0 . 753. 0 0 . 904. 0 本实验中污泥 COD 负荷增大到 0. 67 kg kgd , 而DO 不足 1. 0 mg L ,远远低于“安全”DO 浓度。在稳 定的短程硝化基础上 , 逐渐增大曝气量至 2. 0 mg L。 DO 、 氨氮去除率、 SVI 的变化如图 5所示。 图5 DO 、氨氮去除率与SVI 的关系 可见当逐渐增加 DO 至 2 mg L 时, SVI 降到 118 mg L ,污泥膨胀现象得到有效的控制 , 但是短程 硝化有向全程硝化转变的趋势 。故在运行中可将 DO 控制在 1. 5～ 2. 0 mg L, 在此条件下既能有效缓解污 泥膨胀又能维持亚硝氮的积累 积累率≥90 。 此外可通过排泥将反应器内积累的大量沉降性 能差的污泥及时排走 ,这也是一种改善污泥沉降性能 的手段。 3 结论 1 利用一体式A O 装置,在温度为 27 ～ 30℃, pH 7. 5～ 8. 6,DO 0. 5～ 1. 0 mg L 的条件下实现了稳定的亚 硝氮的积累 积累率≥ 80 ,污泥沉降性能良好。 2 在逐渐增加 N P 的过程中 ,SVI 从 326 mL g 下转第 17 页 14 环 境 工 程 2008年 6 月第26 卷第3 期 说明Cr Ⅵ 在球内都转变成了Cr Ⅲ ,并以Cr OH3 形式存在。因此 ,已使用的球可不经过脱附处理, 直 接磨碎后通过一定方法回收 Fe OH3和Cr OH3,活 性炭可继续用来制备微球 。 3 结论 1 利用液-液相分离方法制备的包埋铁粉和活 性炭的微球 ,其内部铁粉和活性炭分部均匀 ,对铁粉 的利用更加充分 , 并且加快富集在球内的 Cr Ⅵ 和 Fe 2反应速度 , 对含铬废水中的 Cr Ⅵ 有较好处理 效果 。 2 静态实验结果表明 当铁粉和活性炭的包埋 量为 6, 废水初始 pH 值为 2, 处理时间为 4 h ,微球 质量为 10 g 时, Cr Ⅵ 的去除率达 99. 7。动态实 验结果显示 当进水流量 0. 27kg kgd 时发生污泥 膨胀 。 4 DO 从 0. 5 mg L 逐渐增大到 2. 0 mg L 的过程 中,SVI 从 268 mL g 降低到 118 mL g , 但是短程硝化 有向全程转化的趋势 ,本实验中最佳的 DO 应选择在 1. 5～ 2. 0 mg L ,在此条件下沉淀池的固液分离效果良 好,并且氨氮、 COD 去除率和亚硝氮积累率均90。 污泥膨胀现象也能得到有效控制。 参考文献 [ 1] 操卫平, 冯玉军. 高氮低碳废水生物脱氮研究进展. 化工环保, 2004,24 4 266 -269 [ 2] 沈耀良, 王宝贞. 废水生物处理新技术 理论与应用. 北京 中国环境科学出版社, 1999 234 -237 [ 3] 李军, 杨秀山, 彭永臻. 微生物与水处理工程. 北京 化学工业 出版社, 2002 [ 4] Hermanowicz S W.Dynamic changes in populations of the activated sludge community effects of dissolved oxygen variations. Wat . Sci. Tech. , 1987 889 -895 [ 5] 高春娣, 王淑莹. 化工污水处理场污泥膨胀与上浮的原因及其 控制. 哈尔滨建筑大学学报, 1999,32 5 52 -55 [ 6] 张晓玲, 王志盈. 低溶解氧下活性污泥法的短程硝化研究. 中国 给水排水, 2003, 19 7 1 -4 [ 7] 张相忠, 王淑莹.污泥膨胀的研究.哈尔滨商业大学学报, 2002,18 4 464 -467 作者通信处 侯巧玲 730046 甘肃兰州市城关区盐场堡兰州兽医研 究所 E -mail ashly05062163. com 2007- 10-31 收稿 17 环 境 工 程 2008年 6 月第26 卷第3 期 POWDER ACTIVATEDCARBON -MEMBRANEBIOREACTORFORTREATMENT OF MUNICIPAL WASTEWATERPei Liang Yao Binghua7 Abstract The combined process of powdered activated carbonPACand membrane bioreactor MBRwas applied for treatment of municipal wastewater. The removal efficienciesof COD, NH 4-N and turbidity inthe combined processwere investigated. The result showedthat the combined process may achieve better removal efficiencies of COD,NH 4-N and turbidity, when water temperature is above 26℃, DO is above 4. 5 mg L and pH is between 6 and 9. The average removal efficiencies of COD, NH 4-N and turbidity in the combined process were 88, 98 and 98 respectively, and was better than that of single MBR process and conventional process. The effluent COD was less than 22 mg L andNH 4-N was less than 1 mg L, turbidity was less than 1NTU. It was better than that of water for domestic reuse stated by the Ministy of Construction CJ25. 1-89 . The fouled membrane was cleaned by water rinsing ,water -acid rinsing, water -alkali rinsing , which can let its flux be restored to 43, 81, 89 of a new membrane respectively. Keywords powder activated carbon membrane bioreactor domestic wastewater INACTIVATION OF MICROBE IN RUNNING WATER USING MICROWAVE ELECTRODELESS ULTRAVIOLET LIGHTLou Chaogang Xia Dongsheng Zhao Fan et al 10 Abstract E. coli and Bacillus subtilis were selected to express respectively the easily and difficultly inactivated microbe, and the best irradiationtime and the limit turbidity of microwave electrodeless ultraviolet UVirradiation were studied.In this condition, checking the disinfection of E. coli and Bacillus subtilis, and compared with mercury lamp of medium pressure.The results showed that when best irradiation time was 210 s, microwave electrodeless ultraviolet irradiation can achieve inactivation rate of 99. 92.In order to obtain the best results of disinfection effect, the water of turbidity was below 8 NTU, the limit turbidity of disinfection was 40 NTU;microwave electrodeless ultraviolet irradiation can achieve inactivation rate of 100with 180 s, and the Bacillus subtilis inactivation rate of 100with 300 s, it is more effective than mercury lamp of medium pressure disinfection. Keywords E. coli Bacillus subtilis limit turbidity drinking water disinfection efficiency electrodeless UV lamp STUDY ON THE BULKING SLUDGE INTHE PROCESS OF SHORT RANGE NITRIFICATIONOF HIGH AMMONIA WASTEWATERHou Qiaoling WenYibo Li Linbao et al 13 Abstract A O technique was used to treat simulated high ammonia wastewater, the stability short -cut nitrification could be implemented by controlling the right content accumulation rate≥80, the activated sludge had good settling property, in the late of the short-range nitrification it was degraded gradually . It is showed by the experimental results that increasing N P ratio in the wastewater can slightly dropSVI, but still can not effectively ease the sludge bulking.The bulking sludge would be occurredwhen COD load was above 0. 27 kg kgd .Controlled DO with 1. 5 to 2. 0 mg L, the solid-liquid separation result is good, and the removal rates of NH 4-N and COD, as well as the cumulative rate of nitrite nitrogen are greater than 90, sludge bulking can be effectively controlled. Keywords short -range nitrification sludge bulking A O process TREATMENT OF WASTEWATER CONTAINING CrⅥ BY PVA MICRO-BALL ENTRAPPED IRON POWDER AND ACTIVATE CARBONHuang Yi 15 Abstract Micro -ball entrapped iron powder activate carbonwas prepared by liquid -liquid phase separation and its effect on treating the simulationwastewater containing CrⅥ was investigated. The results showed that the removal rate of CrⅥ could reach 99 . 7 at pH value of 2 and treating time of 4 h. The effluent could reach the discharge standardof China, the treatment operated steadily and the iron powder and activate carbon did not agglomerate in the continuous removal process. So this is superior to the common iron -carbonmicro -electrolytic . Keywords entrapping iron powder activate carbon Cr Ⅵ TREATMENT OF NEOPRENE WASTEWATER WITHMICROELECTROLYSIS AND THREE -UNIT BIOCHEMISTRY PROCESSZhang Sheng Xu Lirong Zhu Jianrong et al 18 Abstract A pilot study on the treatment neoprene wastewater with integrated microelectrolysis and three -unit biochemistry process was done. The experiment results under the stable condition showed that COD removal rate was up to 97. 6, COD concentration of the effluent could be reduced to less than 300 mg L. Keywords microelectrolysis three -unit biochemistry process neoprene wastewater treatment of pilot scale DEGRADATION OF SAFRANINE T BY THE TECHNOLOGY OF CATALYTIC OXIDATION Wang Lijuan Huang Jiguo Dong Lili et al 20 Abstract The technology of catalytic oxidation is studied for degrading safranine T. The self-made polyoxometalate Zn1. 5PW12O40nanotube is used as the catalyst and dioxygen is used as the oxidizer. The results show Zn1. 5PW12O40is sutiable for catalyst, with the structure of the Zn1. 5- PW12O40being hollowed, the type of the Zn1. 5PW12O40being affiliated to the type of heteropoly acids, and the scale of the Zn1. 5PW12O40being nanometer -scale; in the oxidation system of air, the optimum reaction time is 4 hours, and correspondently the degradation rate and the degradation velocity are respectively 78 and 665μ g h; the activity and stability are both high, andwhen the circulation times are four, the degradation is still 65. Keywords nanotube dioxygen safranine T degradation rate circulation 2 ENVIRONMENTAL ENGINEERING Vol. 26, No. 3, June ,2008